Apparatus for coding and decoding messages



ay l, 1928.

J. GRASSI APPARATUS FOR lCODING AND DECODING MESSAGES Filed May 21, 1925 5 Sheets-Sheet 1 L AM3 A 9 f S A,

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OPH 3 SEPI s mv s RPAN Wahn APPARATUS FOR CODING AND DECODING MESSAGES Filed May 21, 1925 s sheets-sheet 2 /ME /v To le,

J. GRASSI APPARATUS FOR CODING AND DECODING MESSAGES Filed May zal,v 1923 3 Sheets-Sheet 5 A #WEA/T013,

Patented May l, 192,8.

UNITED STATES 1,667,780 PATENT OFFICE.i

JOSEPH GRASSI, OF LONDON, ENGLAND.

y arraaarus ron coDING Aptucanmniee may 21, '1923, serial in.

Thisinv'ention relates to apparatus for use in coding and decodingmessages, and prou vides an apparatus of simple construction by the use of which a word may be readily 5 transposed into a code word, capablcof pronunciation for transmission by telegra h, letter, telephone, y broadcasting or ot er means. The device permitsof a multitude of different combinations to give different" l code words for the sante original word, a rcorrespondingly arranged apparatus at the other end of which the. message is sent serv# ing to decode the message. nal word cannotV be -ascertained from the l code word unless the particular code `is known.

The invention consists essentially in an arrangement of letters'in the form of a column on an endless lband or equivalent, a number of such columned bands being furnished adjustable in relation to one another. Each column contains two or more complete alphabets of letters arranged in ,varied sequences, and the originalword-itis desired to transpose into code `form is spelled across the columns, having one letter of each column, and the corresponding code word appears at a predetermined distance away from the point where the original word appears, said code word also having a letter of each column. That is to say that for every letter making up the original word, there is a delinite letter on the same column (actually a dierent letter) which serves to make up the code Word. The original word is found from the code word in similar fashion, and in order to facilitate the description, the word which is known whether the original or code word, will be hereinafter referred to 40 as the known word, and the word to be ascertained therefrom as the unknown word.

The apparatus may have a plurality of set points provided around the columns for the formation and reading of the known and unknown words respectively any pair of which may he. used at the same time, for the -formationof the known word and the reading of the unknown word respectively giving di'erent Vkey combinations without changing the position of the columns or alphabets.

rihe apparatus employed for carrying out the invention consists either of a number of endless strips of suitable material arranged side-by-side and adjustably mounted, or a plurality of disc wheels or pulleys rotatably Thus the origi- AND DEconINe iunssaeiis.V

640,546, and in Great Britain June 1, 19.22.V

mounted on a spindle, such'discs or pulle s having the letters arranged on their perip eries, or on their side faces near their peripheries, as hereinafter described.

The invention will be more readily under' stood by reference to the accompanying drawings and following description.

Fig. 1 is a diagrammatic view illustrating the relative arrangement of letters in adjacent columns. l

Fig. 2 is a front elevation'of one form of apparatus embodying the invention.

Fig. 3 is a side elevation partly in section of the constructionshown in Fig. 2. y

Fig. 4 is a front elevation of a modified type of apparatus.

Fig. 5 is an end view thereof.

Fig. 6 is a vertical cross sectional view of the construction shown in Figs. 4 and 5, the line of section being taken through the center of the discs and showing a preferred way of mount-ing the same.

ig. 7 is a cross sectional view illustrating 1n detail one ofthe spindle mountings.

l Fig. 8 is a plan view of avfurther modi' fied type of apparatus.

Fig. 9 is a side elevation of the apparatus shown in Fig. 8.

Fig. 10 is a plan view showing a modified arrangement of the construction shown in Figs. 8 and 9. y

Fig. llis a side elevation of the construction shown in Fig. 10.

Referring to Figure l of the drawings, this merely gives anexample of an arrangement of letters and columns to render the in-` vention clear.

In this view, the spaces or sight windows 2, 2 through which the known and unknown words are indicated are shown disposed such distance away from one another that there is a complete alphabet of twenty-six letters on each column 1, l between them. The separate alphabets on a strip differ from one another in their sequence of letters, and each has an index number or key to identify it, and as the vstrips may be interchanged each strip has an index number, so that any particular one may be determined. rlhus, on the extreme left hand strip, considering the upper space 2, is the numeral 12, the :first ligure, viz l of which indicates the particular strip. and the second figure, viz 2 of said number, the particular alphabet on that strip, said numeral 12 constituting what will be termed a key. lit is to be understood that lll!) liti if each strip or band 1 had four alphabets thereon it would be equipped with four keys each key being arranged 1n the space between theadjacent alphabet and the alphabet numbered consecutively 1, 2, 3, 4 these numerals being placed at the right of two digits, the left digit being. the one indicating the number of the strip on which the alphabets were applied. For instance. as above pointed out, the key 12 shown in Fig. l would indicate that the strip was numbered 1 and the alphabet numbered 2. Likewise the numeral 13 on said strip would indicate alphabet number 3 and strip number l and so on.

Consideringr the second and third strips from the left, it will be observed that the vowels are equidistantly spaced apart. For example, a number of vowels might occupy consecutivespaces provided a vowel in the known word gives a corresponding vowel in` the unknown word. The spaces 2 are arranged such a distance apart that when a vowel appears on one strip through one space 2, a vowel also appears in the other space on the same strip. The same applies to consonants. As an example, the word five is spelled in the upper space and gives the word somo (in `this particular instance), in the lower space, which is capable of pronunciation. Both the vowels and the consonants are arranged in a specially calculated order so that all the letters in the unknown words will always be different Afrom the corresponding letters in the known words.

Since the alphabets on a single strip each have a different sequence of letters, the code may be altered byturning any one or more strips so'that another alphabet comes into use, and, if the arrangements of letters on various-strips each difi'er fronrone another, the,` code may be altered by interchanging the strips. That is to say it'is possible,- in a practical and easy way to continuously change combinations of keys for each word of a message, without changing once the respective positions of columns and alphabets. For instance, with fouralphabets to a column, one has at his disposal twelve different combinations of keys which one can use in any sequence that may be pre-arranged with a correspondent. The absolute difference from one another of the translations resulting from these twelve combinations of keys, can be proved by transposing the same known word in each ofthe' twelve combinations of keys, and by comparison it will be found that the resulting twelve unknown words will have allot the consonants different from one another. This so far as known hasnever been eiected before and insures absolute secrecy. Thus the device is capable of a vast number of diierent codes, and the code word if picked up can only v'be transposed to the original word if the particular arrangement of sets and alphabets on the decoding machine is in agreement with `that by which the word was originally coded.

side members 3, 3 andcross members 4, 4.

Transverse rods 5 are arranged near therespective ends of the frames, and rollers 6 are rotatably mounted thereon. Endless bands 1, 1 are carried on said rollers and the spaces for the known and unknown words are formed between spaced pairs of transverse bars 7, 7 each two forming sight windows or frames transversely of the movable members or bands through which the code notes and `index symbols of the index members will appear. Each pair of bars 7 is slidably mounted on the side members of the frame by extension parts thereof running in longitudinalgrooves 8, 8 in the said side members. A similar arrangement may be furnished at each side of the device. The endless bands 1, 1 may be of' rubber tape or any other desired material and may be made adjustable as to tension by mounting one of the rods 5 in slots and em )loying plates 9. 9 pivoted to the frame and' urnished with alternative notches for pressing` against said rod, giving a stretching effect to the strips.

Another convenient form of apparatus for carrying out the invention' is shown in Figures 4, 5, 6 and 7 and employs a number of discs 10, 10 having the letters formed on their periphery, said discs being independently rotatably mounted on a spindle 11. Figure 4 is a front view and shows the spindle 11 carried by bearings in standards 12 at each of its ends. Figure 5 `is ,an end view thereof.

Figure 6 is a cross sectlon through the centre Aof the discs and shows a preferred meth.

od of mounting same. .That is' to say said discs are revolubly mounted ena sleeve 13 flanged at each end, one of said flanges 14 or both being detachable. This arrangement permits easy insertion ofthe discs into position, as same are placed en bloc into posi-- tion, the spindle 11 being simply passed through the`sleeve 13 and the bearings in the standards 12.-.

When the known word has been formed, the discs are rotated, en bloc in order to ascertainnthe unknown word, and in order to connected across by spindles 17. One of said spindles is constituted by a split tube 18, hingedly mounted to one of the arms 16 so as to be capable of swingingl away from the periphery of the discs and is adapted to reoeive a spindle 19, as seen in Figure which is a cross-section therethrough. Said Spindle 19 is furnished with a longitudinal key 20, which key projects through the slit in the tube, andsaid key adapted to engage in grooves 20"L on the periphery of the discs. That is to say, between the adjacent letters of each disc, a transverse groove`20a is formed, and at the division of the alphabets on each disc there is provided a projecting pin 21, the arrangement being such that as the desired letters on the respective `discs are consecutively arranged in position,

they are locked by pushing the spindle 19 'into the tube, its key 20 engaging in the ooves 20a ad'aoent the letters, the projecting pins 21 o the unlocked discs, by contacting with the spindle 19, preventing said unlocked discs making a complete revolution, and consequently preventing the erro-v neous passing from one alphabet into another alphabet while said spindle is in position.

In use, the known word is formed along the edge of the spindle 20, and the unknown word read-oli along the edge of one of the other spindles 17'.

A simpler construction of apparatus embodying the invention is` shown in Figures 8 and 9 being a plan and edge view' respectively. Such apparatus comprises a'base 22 having a spindle 23 on which are concentrically mounted a plurality of discs 24 o'f varying diameters the largest bein(lr at the bottom so that part of one disc oveaps the edge of the disc' above it forming in effect a rim 24a on which. letters are formed or arranged. Each rim is formed with the same number of letters, which are adapted to register.

In Figures 10 and 1.1 is shown a modification of the last described construction, Figure 10 being an elevation and Figure 11 vertical section through line .fr-:1: thereof. The discs 25 are of equal diameters arranged in staggered relation, each being pivoted to a strut 26 and the struts are so arranged that the pivots are equidistantly spaced apart, so that a crescent shaped part of an underneath disc projects on one side over the edge of the disc above. The discs are arranged on each of their lsides with letters near their peripheries said letters being arranged in such a manner that the original \word is composed by the letters on the crescent shaped projections such as 25a on one` the code word appearing on the similar shaped projecting parts 25b of the discs on their other sides. The struts 426 are held together by means of a support 27 having a part 28 which encircles them and rigidly holds them in position until required to be released for interchanging. The struts 26 and support 27 are formed with apertures enabling the letters on the discs to be seen side,

7 therethrough.

With a device of this character constructed of ten disks as shown in Figs. 4, 5 and 6, and each disk having four alphabets on its periphery it is obvious that the instrument would contain ten sets of four alphabets each, there being four keys and Jforty alphabets in all. With four keys twelve different key combinations may be formed or the formation of the known word and the reading of the unknown wordand if one word of the ordinary language were coded in each of the twelve combinations of keys of one single position of the instrument, it would be found that the resulting twelve code words would have all the corresponding consonants different from one another and from the corresponding Iconsonants in the original word; and the corresponding vowels in the known and the unknown word would never be the Same. The arrangement of disks, alphabets and keys is very simple and is obtained as follows The first letter space of each alphabet carries two separate digits the left digit from naught to nine indicating the disk number while the right digit from naught to four indicates the number of the alphabet on the disk, for instance 94 would show that the disk number was 9 and the alphabet number was 4, and since the alphabets of each disk are numbered consecutively \1, 2, 3 and 4 it is necessary to know only one key of any position of the instrument in order to ascertain the remaining keys at the same position.

It will thus be seen that by employing a prt-,arranged sequence of the twelve combinations of keys it is only necessary to know one key and to register the instrument in that key, in order to put all the other keys and all `the twelve key combinations also in register ready :for operating without bothering about any other indication.

Thus with the four alphabets of this apparatus the same known word may be found in key 1 and the .unknown word read lin keys 2, 3 and 4; the same known word being formed in key 2 and the unknown word read in keys 1, 3 and 4; the Same known word formed in key 3 and the unknown word 'read in keys 1, 2 and 4; and wherrthe same known word is formed in key 4 the unkno'wn lil) word is read in keys 1, 2 and 3 therebyv providing twelve code words having no similarity whatever onewitli the other or with the original word, without requiring any interchan'ging of the columns or moving them forwards or backwardsA for the purpose of changing keys, using one single position of the apparatus only. Thus these .twe'lve combinations of keys of one single p osition of the apparatus may be employed in any 'sequence desired using a different combina-I tive alphabets being different from cach other, the vowels occuring in one alphabet of each unit' occupying spaces corresponding with the spaces occupied by the vowels of the other alphabets of the same unit, differ-vent vowels occuring upon the corresponding vowel spaces of the respective alphabets of each .unit and designating characters appearing upon the .caption spaces. v

2. For coding and decoding apparatus, a unit having a surface divided into 4ra plurality of alphabet spaces and intervening caption spaces, each alphabet space having thereon the characters of a complete alphabet arranged in, abnormal sequence, the. arrangement of the characters of the' respective alphabets of `said unit being different from each other, vowels occurring in one alphabet of eaehunit occupying spaces corresponding with the spaces occu ied by the vowels of the other alphabets ci) said unit, different vowels occurring upon thecorresponding vowel spaces of the respective alphabets, alphabet ldesignating characters appearing upon thecaption spaces7 and unit locating characters appearing upon the caption spa-ces.

3. Apparatus for coding `and decoding secret messages consisting of a plurality of columns adjustable lto one another and interchangeable with each other, each column containing a plurality of al liabets where-v by the known word can e formed andthe unknown word can be read across all columns, characterized by this that each colunin of letters indicated on the columns 'con- -tains a plurality of alphabets so arranged that-.each vowel of an alphabet always corresponds to anothery but different vowel of another alphabet of the same column, and

similarly a. consonant to another but different consonant in the other alphabet or alphabets, so that for each known word a code word may also be formed containing an equal number of vowels and consonants as the known word.

4. In a coding and decoding apparatus means for forming known words at certain positions across the apparatus, whereby unknown words automatically appear at other positions, said n1eans'\comprising a plurality of alphabets and a plurality ot' keys, and means employing a diierent combination of alphabets for each letter of al word and for each word a different combination of keys.`

5. In a coding and decoding apparatus means for forming known words at certain positions across the apparatus, whereby unknown words automatically ap-pear at other positions, said means comprising a plurality of separate, interchangeable columns, said columns being independently movable and adjustable relatively to each other, each column having a plurality of alphabets arranged in an unbroken line and each alphabet comprising twenty-six letters and intervening caption spaces between the alphabets, the letters of the respective alphabets being differently arranged relative to each other, the same sequence of consonants and vowels being maintained for all vthe alphabets of one column, with the sequence in each column different from that in the others.

6. Apparatus for coding and decoding secret messages consisting of a plurality of columns adjustable to one another and interchangeable with eachother, each column containing a plurality of alphabets whereby the known words'mayrbe formed and the unknown words read across all columns, cach column containing a plurality of alphabets, the spacing of the vowels in all the valphabets being irregular, such irregularity being different from each column but similar in allthe alphabets of the same columns.

7. Apparatus for coding and decoding secret messages consisting of a, plurality of columns adjustable to one another andinterchangeable with each other, each column containing a plurality of alphabets whereby the known words may be formed and the unknown words read across all columns, each lcolumncontaining a plurality of alphabets,

the vowelsand consonants which are arranged in specially calculated order whereby all the letters in the unknown word always differ from the corresponding Letters in the known word.

In testimonywhereofi have affixed-Y my signature hereto this 9th day of May, 1923.

JOSEPH GRASSI 

